\left( \begin{array}{c}\frac{1}{2} \end{array} \right)
 \left( \begin{array}{cccc}i & -1 & 1 & -1\\
 -1 & i & 1 & 1\\
 -i & 1 & 1 & -1\\
 1 & -i & 1 & 1 \end{array} \right)